Field of the Invention
The present invention relates to event detection, and, in particular, to a technique for detecting an event from an image sequence.
Description of the Related Art
Examples of proposed methods for appropriately detecting an event in a moving image include methods discussed in Japanese Patent Application Laid-Open No. 2006-79272, and in “Detection of Abnormal Motion from a Scene Containing Multiple Person's Moves” written by Takuya Nanri and Nobuyuki Otsu, which is provided in Transactions of Information Processing Society of Japan, Computer Vision and Image Media, Vol. 45, No. SIG15, pages 43 to 50, published in 2005. According to the methods discussed in these literatures, Cubic Higher-Order Local Auto-Correlation (CHLAC) is extracted from a moving image, and an abnormal value is calculated by the subspace method, whereby an event is detected from the moving image.
However, the methods based on the subspace method discussed in the above-described literatures require a normal motion to be defined in advance and a large amount of moving image sequences to be prepared for this normal motion.